package studentSysterm1;

import java.util.ArrayList;
import java.util.Random;

public class code {
    public static void main(String[] args) {
        Random r=new Random();
        StringBuilder sb= new StringBuilder();
        ArrayList<Character> list=new ArrayList<Character>();
        for (int i = 0; i < 26; i++) {
            list.add((char) ('a'+i));
            list.add((char) ('A'+i));
        }

        for (int i = 0; i < 4; i++) {
            int index = r.nextInt(52);
            sb.append(list.get(index));
        }
        int num = r.nextInt(10);
        sb.append(num);
        String s = sb.toString();
//        System.out.println(s);
        char[] chars = s.toCharArray();
        int index1 = r.nextInt(5);
//        System.out.println(index1);
//        char c = chars[index1];
        char temp=chars[4];
        chars[4]=chars[index1];
        chars[index1]=temp;


        System.out.println(new String(chars));
    }
}
